AB-453068-3 ESOPHAGEAL TEMPERATURE AND ESOPHAGEAL DAMAGE IN HIGH POWER SHORT DURATION ABLATION SETTINGS

Abstract

Radiofrequency ablation (RFA) of atrial fibrillation (AF) using high-power short-duration (HPSD) ablation settings (50W, 10s or up to 90W, 4s) are increasingly common, seeking to maximize resistive rather than conductive heating to limit the risk of esophageal damage. The real-time luminal esophageal temperature (LET) response and the risk of esophageal damage of HPSD are not fully established. To investigate the LET and esophageal risk of HPSD RFA on the posterior LA wall. We ablated the deep inferior pulmonary vein (IPV) in close proximity to the esophagus in 14 pigs, using either Termocool SmartTouch Catheter (HPSD 50W/10s, n=7), or QDOT Catheter (HPSD 90W/4s, n=7). LET was monitored with a 12-sensor CIRCA probe. RFA was delivered in the IPV in apposition with the esophagus as verified on 3D maps. We collected LET, ablation parameters; endoscopy, macro- and microscopic examination of the esophagus. In 3 pigs in each group, survival was prolonged 1 month for chronic characterization of esophageal lesions. Total energy delivered (90W/4s vs. 50W/10s) was higher in QDOT group (60.8±18.8W vs. 48.9±0.1W, p<0.005), as was the peak temperature at ablation catheter tip (51.2±3.1°C vs. 25.3±2.8°C, p<0.005). Peak LET was lower in the 90W/4s group than in the 50W/10s group, (38.7±1.5°C vs. 40.5±3.1°C, p<0.005). Temperatures >40°C were reached in 14/90 90W/4s ablations vs 43/94 in 50W/10s ablations (p<0.001). Acute esophageal lesions were found in all pigs. In the 90W/4s group, acute lesions involved affecting outer muscularis layer in 4/4 and up to submucosa in 1/4. However, no chronic lesions were identified in 3/3. In the 50W/10s group: 4/4 acute lesions involved entire muscularis layer into the submucosa, and reaching the mucosa in 2. Chronic lesions were found in only 1 on pig in the 50W/10s group – complete muscularis layer replacement with scar (with submucosal inflammation). All lesions occurred after high LETs. (Figure) HPSD 50W/10s can create high LET and significant acute and chronic esophageal damage. QDOT catheter at 90W/4s leads to lower peak LETs, can lead to acute lesions but no chronic esophageal damage. LET can be used to monitor risk of esophageal damage in both HPSD protocols.